Wilms' tumor - Role of fine needle aspiration and DNA ploidy by image analysis in prognostication

OBJECTIVE To evaluate the utility of cytomorphologic features and DNA ploid y estimation in fine needle aspirates (FNAs), from Wilms' tumors for progno stication. STUDY DESIGN: Twenty-three cases of Wilms' tumor having FNA and follow-up d ata were selected, Cytomorphology was analyzed by two observers. DNA ploidy was determined in 19 cases by image cytometry by destaining Papanicolaou-s tained slides and restraining with Feulgen stain. Various parameters and pa tient outcomes were compared, and statistical evaluation was done. RESULTS: Poor outcome (12/23 cases) was associated with age <2 years (P=.01 ), severe pleomorphism of blastemal cells (4/23 cases, P<.05), very large n ucleoli (5/23 cases, P=.075), atypical mitosis (6/23 cases, P=.032) and ane uploidy/tetraploidy of tumor cells (6/29 cases, P=.005). Term unfavorable c ytology is proposed when a combination of severe pleomorphism, very large n ucleoli and atypical mitosis is seen in FNA smears. Four Wilms' tumor FNAs were characterized as showing unfavorable cytology, and all had a poor outc ome (P=.0351). Three of the six cases with aneuploid/tetraploid features al so showed unfavorable cytology. CONCLUSION: Unfavorable cytology and aneuploidy/tetraploidy in FNA smears o f Wilms' tumor are associated with it poor prognosis.